Field of the Invention
The invention relates to a guiding device for a freshly printed sheet, the leading edge of which sweeps over an imaginary conducting surface along a sheet travel direction perpendicular to the leading edge of the printed sheet, with a sheet-guiding surface following the conducting surface and located at a distance therefrom, the sheet-guiding surface being formed on a guide-plate arrangement and having blast-air openings distributed thereover and terminating therein; the invention relates further to a sheet-fed printing press with such a guiding device.
A guiding device of the aforementioned general type has become known heretofore, for example, from the published German Patent Document DE 43 08 276 A1, wherein blast-air nozzles are fitted into penetrations formed in a guide plate, the blast-air nozzles emitting during operation a blast-air jet out of flow channels which are disposed at an inclination to the sheet-guiding surface and leading into or terminating in the sheet-guiding surface. According to an exemplary embodiment of the thus known guiding device, the flow channels are aligned in the sheet travel direction and the blast-air nozzles are distributed over the sheet-guiding surface. The blast air escaping during operation from the flow channels produces an air flow between the sheet and the sheet-guiding surface, the intention being that the air flow should prevent contact between the sheet and the sheet-guiding surface.
A guiding device for sheets has become known heretofore from the published European Patent Document EP 0 502 417 A1, the guiding device being composed of a plurality of nozzle tubes extending in the sheet travel direction below the conducting surface which is swept by the leading edge of a sheet. Leading into or terminating at the upper side of these nozzle tubes are blast-air openings of blast-air nozzles which are inserted into the nozzle tubes, turbulent flows sweeping over the sheets being producible thereby.